Alright, let's work through 5151 times 6309 step by step
5151 × 6309 = 6309 × (5151)
+ 6309 × 1 giving us 6309
+ 6309 × 50 which equals 315450
+ 6309 × 100 that is equal 630900
+ 6309 × 5000 that results in 31545000

= 32497659
